The invention relates to a dishwasher machine, in particular a domestic dishwasher machine, comprising a washing container and devices for washing items to be washed by means of washing solution, a control device, at least one wash program comprising the partial program steps “clean”, “intermediate rinse”, “clear rinse” and “dry” and comprising a sound wave generator for acting upon the interior of the washing container (2) with sound waves. The invention further relates to a method for cleaning items to be washed in a washing container of a dishwasher machine, in particular a domestic dishwasher machine, comprising the partial program steps “clean”, “intermediate rinse”, “clear rinse” and “dry” and wherein the interior of the washing container is acted upon by sound waves.
Conventional dishwasher machines are known to comprise a washing method whose program sequence generally consists of a partial program step “pre-wash”, a partial program step “clean”, at least one partial program step “intermediate rinse”, a partial program step “clear rinse” and a partial program step “dry”.
Various drying systems are known for drying the items to be washed in a dishwasher machine. For example, so-called condensation drying is used in which the items to be washed are heated to high temperature, usually 65° C., in a partial program step preceding the “dry” partial program step in order to evaporate the moisture as a result of the high temperature of the items to be washed (self-heat of the items to be washed) and/or the washing container. However, this procedure has the disadvantage that a considerable quantity of energy must be expended to heat the items to be washed. In addition, there are drying systems provided with a fan which circulates the air in the washing container and dries this circulated air outside the washing container e.g. as a result of condensation on cold surfaces and then preferably re-heats this air again before returning it into the washing container.
In addition, so-called sorption drying devices are known from DE 103 53 774 A1 of the applicant in which moist air is guided from the washing container onto a reversibly dehydratable material which extracts the moisture from the moist air. Since the moisture absorption capacity of the reversibly dehydratable material is limited, the reversibly dehydratable material is regenerated at a different point in time from the drying process. Compared with condensation drying, this method has the advantage that the drying of the items to be washed requires a considerably lower expenditure of energy. A disadvantage, however, is the somewhat more complex design of the dishwasher machine since additional components and lines must be provided in an area located outside the washing container.
Known from U.S. Pat. No. 3,854,998 is a dishwasher machine provided with an ultrasonic generator which acts upon the washing solution used to clean the items to be washed with ultrasonic vibration to enhance the cleaning performance. As a result of the design-dependent generation of ultrasonic vibration using water vapour and hot air which is intended to set in vibration the washing solution emerging from the washing device, the ultrasonic wave generator cannot be used for other purposes. In addition, the design configuration does not allow the use of dishwasher machines conventionally used nowadays in which two washing devices each allocated a holder for items to be washed are provided.
In addition, WO 91/01473 discloses an ultrasonic drying device, among other things for drying crockery. This comprises a power amplifier and/or an oscillator circuit, a transducer and a device for transmitting or focussing the ultrasonic waves. The sound wave can be generated using a compressed air source or an ultrasonic whistle.